A novel method is proposed for the identification of essential genes whose products will be developed as new antibiotic targets. A combination of transposon mutagenesis and Bacterial Artificial Chromosomes (BACs) in Staphylococcus aureus and Enterococcus faecalis will yield cells that require BAC complementation of transposon mutations in essential genes. Phase I of this project includes the steps involved in constructing BAC libraries of S. aureus and E. faecalis. Phase II of the project will entail using the BAC libraries with transposon mutagenesis to identify essential genes and to develop screens for new antibiotics based on these essential genes. The method proposed for identifying essential genes is rapid, applicable to haploid cells whether prokaryotic or eukaryotic, and is amenable to automation. PROPOSED COMMERCIAL APPLICATIONS: Elitra is creating a unique relational database of both targets & drug screens for major gene/protein targets across multiple pathogens. This database will markedly enhance the ability of Elitra and its corporate partners to make informed decisions about which novel targets to pursue. Elitra is building a unique, ultra rapid Gene-to-Screen technology platform that will allow miniaturized drug screens to be developed for any validated target in its proprietary database within 2-3 weeks. Screening for new antibiotics will begin by the 4Q.99 when the in-house chemical screening library will be in excess of 250,000 compounds.